The incidence of KRAS2 mutations in human compared to mouse lung tumors differed significantly, as did the incidence of Hras and p53 gene mutations in human compared to mouse liver tumors.
Experimentally induced liver tumors in mice harbor activating mutations in either Catnb (beta-catenin) or Ha-ras, according to the carcinogenic treatment.
The high prevalence of Ha-ras and B-raf mutations in mouse liver tumors is in striking contrast to human hepatocellular cancers which very infrequently harbor mutations in the two genes.
The frequency of liver tumors and glucose-6-phosphatase-altered liver lesions was almost identical in all three P53 genotypes and approximately 40-50% of liver tumors showed activating mutations in codon 61 of the Ha-Ras gene independent of genotype.
These results indicate that spontaneous liver tumors in rasH2 Tg mice contain different mutation patterns depending on the histologic type or cell origin of the tumors (i.e., hepatocellular carcinomas or hepatic hemangiosacomas).
Erb (B), erb (A+B), Ha-ras, myc, fos and fms oncogene expression elevated in certain stages of fetal liver development and in hepatoma as compared to the normal adult human liver.